School of Environment, Tsinghua University, Beijing 100084, China.
School of Environment, Tsinghua University, Beijing 100084, China.
J Hazard Mater. 2021 Feb 5;403:123811. doi: 10.1016/j.jhazmat.2020.123811. Epub 2020 Sep 14.
The elimination of benzene, a typical volatile organic pollutant, is one of the most challenging topics for environmental scientists. Catalytic oxidation technology is considered the most efficient approach for its elimination. Herein, we report the successful preparation of a novel α-MnO-like rod catalyst via an acid etching route and propose YMnO mullite as a novel precursor. The optimized α-MnO-like rod catalyst showed significantly improved benzene oxidation activity compared to the raw YMnO and commercial MnO catalysts, resulting in 100 % benzene conversion at 200 °C at a GHSV of 60,000 mL g h. Notably, the α-MnO-like rod catalyst performance at lower temperatures (100-175 ℃) exceeded that of a commercial Pt/AlO catalyst. The excellent catalytic performance of the α-MnO-like rod catalyst is associated with its low-temperature reducibility and abundant surface-active oxygen species. During the acid etching process, more Mn is oxidized to Mn, and more surface oxygen vacancies are generated on the α-MnO-like rod catalyst, which provides more adsorption sites for oxygen molecules to promote the benzene oxidation reaction. The α-MnO-like rod catalyst should be a great alternative to commercial noble metal catalysts for the elimination of volatile organic pollutants, especially at lower temperatures.
消除苯这种典型的挥发性有机污染物是环境科学家面临的最具挑战性的课题之一。催化氧化技术被认为是消除苯的最有效方法。在此,我们通过酸蚀路线成功制备了一种新型的α-MnO 类似棒状催化剂,并提出 YMnO 莫来石作为一种新型前体。与原始 YMnO 和商业 MnO 催化剂相比,优化后的α-MnO 类似棒状催化剂表现出显著提高的苯氧化活性,在 GHSV 为 60000 mL g h 的条件下,在 200°C 时苯的转化率达到 100%。值得注意的是,α-MnO 类似棒状催化剂在较低温度(100-175°C)下的性能优于商业 Pt/AlO 催化剂。α-MnO 类似棒状催化剂具有优异的催化性能,这与其低温还原性能和丰富的表面活性氧物种有关。在酸蚀过程中,更多的 Mn 被氧化为 Mn4+,α-MnO 类似棒状催化剂上产生更多的表面氧空位,为氧分子提供更多的吸附位点,从而促进苯氧化反应。α-MnO 类似棒状催化剂应该是商业贵金属催化剂的理想替代品,可用于消除挥发性有机污染物,特别是在较低温度下。